zeller



Feb. 7, 1956 E. B. ZELLER 2,733,749

ROLLER PUNCH AND DIE Filed Feb. 2, 1953 nvvawron E. B. ZELLER ATfOR NEV United States Patent 'Electric Company, Incorporated, New York, N. Y., a

corporation of New York Application February 2, 1953, Serial No. 334,402

4 Claims. 01. 153-21 This invention relates to apparatus for sizing articles and more particularly to roller punches and companion dies for shaping articles to exact sizes and sharpening the corners thereof. In the manufacture of hollow articles such as rectangular tubular members or metal containers, where the contours of, the corners are unimportant and may have cross-sectional arcs of various radii depending on the type and thickness of material used in their formation, the conventional types of forming punch and die units may be employed.

For some applications, however, rectangular tubes or otherarticles must be made tovery accurate dimensions with vsharp internal corners which cannot be formed with ordinary punches and dies.

An object of the present invention is an apparatus of the punch and die type which is simple in structure and highly accurate insizing articles and sharpening the corners' thereof. i

i' With this and other objects of invention, the" apparatus comprises a punch which is adapted to enter an article having a corner to be sharpened, the punch having a recess in a portion thereof disposed for registration with the corner, a die having a cavity adapted to receive the article and a roller, having a peripherial cross-sectional contour similar to the cross-sectional contour into which the corner of the article is to be formed, rotatably mounted in the recess and cooperating with the die during relative movement of the punch and die to sharpen the corner of the article.

In the present embodiment of the invention, the punch is rectangular in general contour having side and end surfaces cooperating with like surfaces of the die cavity to efficiently size a rectangular article. This particular punch has recesses at the corners to rotatably receive sharpening rollers having a peripherial contour which are right-angular in cross-section to cooperate with grooves disposed in the corners of the die cavity whereby the materials at the corners of the article may be stretched laterally during relative movement of the punch and die to sharpen the corners into right-angular contours.

Other objects and advantages will be apparent from the following detailed description when considered in conjunction with the accompanying drawing wherein:

Fig. 1 is a side elevational view of a press embodying the apparatus;

Fig. 2 is an isometric view of the die;

Fig. 3 is an isometric view of the punch and pressure 2 portion are rounded as the article is a result of formation in a commercially known punch and die. Fig. 6 illustrates the finished article with the sides and ends of the rectangular portion formed to the required dimensions and the corners thereof sharpened to produce a true rectangular formation.

The apparatus. for accompanying this result is embodied in a press 15 having a bed 16 and a reciprocable ram 17. A die 18 is removahly mounted on the ram 17 and includes a cavity 19 havingside and end surfaces 20 positioned relative to each other according to the required dimensions of the finished article and having outwardly projecting portions 21 conforming to the portion 12 of the article. Vertically extending grooves 22 are formed in the die at the corners of the cavity to free the material adjacent the corners of the portion 11 of the article for stretching during sharpening of the corners.

A punch 25 having a rectangular contour is provided with side and end surfaces 26 conforming to the required inner dimensions for the article. The punch 25 is mounted on a punch holder 27 which is fixedly mounted on the base 16 of the press. The upper corners of the punch 25 are provided with recesses 28 to receive rollers 29 which are rotatably mounted on their spindles 30 accurately located so that the peripheries of the rollers will be positioned so that the corner lines the punch, if extended, would be tangent thereto and lines of the two peripherial surfaces at the tangent point will lie in the planes of .the adjacent surfaces. The cross-sectional contours ofthe peripheries of the rollers are right-angular and are to cooperate with the grooves 22 of the die as illustrated in Fig. 4 to stretch the material of the article at the corners thereof and'tosharpen it into truly rightangular contours.

A pressure pad 32, having a rectangular aperture for the punch 25, has integral portions 33 adjacent the aperture of the required inner dimensions of the portions 12 of the article, to initially receive and support the article and to cooperate with the punch and particularly the die in accurately sizing the article. The pressure pad is supported by a plurality of pins or rods 35 which extend downwardly through apertures in the die holder 27, the base 16 and also a support 36 for the press to a position where it is connected to the conventional type of air cushion, namely an air cylinder supplied with air at a given pressure which is suflicient to move the pressure pad to its normal position, shown in Fig. l, and which may be compressed during lowering of the die.

Considering now the operation of the apparatus, let it be assumed that the apparatus is in the open position, shown in Fig. 1, during which time one of the articles as shown in Fig. 5 may be disposed on the pressure pad. The projections 33 thereof entering the portion 12 of the article to position the article in general alignment with the punch 25 and the cavity 19 of the die. The press may be operated causing downward movement to the ram to move the die 18 to the end of its stroke during which movement the article will be held by the pressure pad until it is received in the die 19 with the corners of the rectangular portion of the article disposed adjacent their respective grooves 22. Further movement of the die will cause the surfaces 20 of the die cavity to cooperate with the surfaces 26 of the punch to size the rectangular portion while at the same time the rollers 29 will stretch the material at the rounded corners of the preformed article to sharpen them to perfect right angle corners, as shown in Fig. 4. This operation continues during the sharpening of the corners until the die has reached the end of its stroke, at which time, the portions 21 of the die cavity cooperate with the portions 33 of the pressure pad which, at this time, will be resting firmly on the die holder 27, to accurately form the portion 12 of the article. It will Patented Feb. 7, 1956 3 be: noted that an annular. bead-like portion 40" of the article will be disposed between the lower surface of the die 18 and the upper surface of the pressure pad where it will receive its final formation.

During opening of the apparatus, that is,. during verti: cal. movement of- -the ramtand. the die, theairtcushionrfor the pressure pad will'force itupwardly to. eject the article from the punch-25. Ifdesired, aspring pressed or otherwise actuated element may bedi'sposed inthe. die. cavity 19 to prevent the finished article from being retained therein.

This apparatus is the solution, to the problem of. accurately sizing hollowarticles and for sharpening corners in materials, particularly in hollowrectangular articles.

It is-tobe understood. that the above described arrange.- ments are simply illustrative of the. application of the principles of theinventionp Numerous other arrangements may bereadily devised by those skilled in, the art which will embody'theprinciples of the invention. and fall within the spirit and scope. thereof.

What is claimed is:

1; An apparatus to sharpen a cornerof an article comprising a punch adapted to enter an article having a corner to be sharpened, the punch having arecess in a. portion thereof disposed for registration with the corner, a roller, having a peripherial cross-sectional contour of a sharp angle, rotatably mounted in the recess of the punch, and a die having a cavity to receive. the article and a groove adjacent the corner to free the materialv of the article adjacent the corner to be formed into a sharp angle by the roller during relative movement of the punch and die.

2. An apparatus to sharpen a. corner of an. article comprising a punch adapted to enter an article having av corner to be sharpened, the punch having a recess in a portion thereof disposed for registration with the corner, a roller, having peripherial surfaces disposed, cross-sectionally, at given angles with respect to each other and the central radius of the roller, and. a die having a cavity to receive the article and a groove adjacent the corner to free the material of the article adjacent the corner to be 4; stretched by the roller during relative movement of the punch and die.

3. An apparatus to' sharpen cornersof a hollowarticle comprising a punch adapted to enter an article having corners to be sharpened and having recesses in portions thereof adapted for registration with the corners of the article, and rollers, having peripherial cross-sectional right angular contours substantially; identical to cross-sectional right angular contours intowhich the. corners are to be formed, rotatably mounted in the recesses of the punch, whereby the corners of the article. may be sharpened into right angles during relative movement of the punch and die, and a die having a cavity to receive the article and grooves adjacent the. corners thereof to free, the material of the article adjacent its corners to be stretched by the rollers during sharpening of the corners.

4. An apparatus to size a hollow article and sharpen the corners thereof, the apparatus comprising a punch, adapted toenter a hollow article, having surfaces. conforming. to the required dimensions for inner surfaces of the article. and recessesv adjacent the: junctures of the surfaces, a die having a, cavityto receive the. hollow article 1 with surfaces conforming to the required dimensions for the.- outer surfaces of the article, rollers, having peripherial cross-sectional contours substantially identical to the cross-sectional contours into which-the corners are to be formed, and a. pressure pad apertured for the punch and having portions adapted to enter the hollow article and cooperatewith thepunch and dieto size the article during relative movement of the die, pressure pad and punch to cause the rollers to sharpen the corners of the article.

References Cited in thefile of this patent UNITED S'IAT'ES PATENTS U "Lib -aw 

